Introduction to Functions
Writing a Linear Equation to Describe a Graph

A really important skill to have in math is being able to recognize and describe patterns. Sometimes patterns are given to you in numbers and that's something that you work on with your algebra skills. Sometimes patterns are given to you just with pictures and you guys can write an equation to describe a pattern of pictures without even knowing any fancy schmancy algebra. So that's the thing I want you to be practicing.

One thing you want to look for when you're given a set of pictures is which piece of the picture stays the same all the time and then which piece of the picture is changing. If you can keep those things straight in your head, you'll be able to figure out how to write an equation to describe the number of boxes or triangles or how to describe the changing patterns that's given to you in a picture.

a) Write an equation to describe the number of boxes in the pattern below:

 0 1 2 3

b) How many boxes would the 8th picture have?
Solution:

a) f(x)= 3x+2
b) f(8)=3(8)+2=24+2=26